It may work in versions below what we specified, it's just that we only support TS12 SP1 HF4 on this paticular engine. As for supporting pre SP1 versions, that is still happening. We wont be making any changes to support until Jan 1, 2015. At that point going forward nothing below TS12 SP1 will be supported. Let's not forget we are pretty much weeks at this point from T:ANE... We want to take advantage of the latest changes and features the software offers us so that we may pass this onto our models. There are a number of things that we can do in SP1 that we can't in other versions, there are also other fixes and improvements we want to take advantage of.
Hope that helps!
Mike